1. Field of the Invention
The present invention relates to a vehicular child safety seat placed on a seat of a car and fixed to the seat of the car with a waist belt included in a seat belt provided on the seat for holding a juvenile.
2. Description of the Prior Art
Following the recently increasing requirement for improvement in safety of automobiles, a vehicular child safety seat has been developed as an apparatus for attaining safety for a newborn, an infant, a child or a schoolchild (generically referred to as a juvenile) riding in a car.
FIG. 8 shows an example of a conventional vehicular child safety seat 1. The vehicular child safety seat 1 is employed for providing a high seat surface for a juvenile having a short trunk fastening a seat belt including a shoulder belt so that the shoulder belt does not hang on the face of the juvenile, and generally put on the market in the name of "booster". This type of vehicular child safety seat 1 is fixed to a seat (hereinafter referred to as "car seat") of a car with a waist belt included in the seat belt provided on the car.
The vehicular child safety seat 1 includes a seat surface 11 and side walls 12. Each side wall 12 has a waist belt engaging portion 13 and a shoulder belt engaging portion 14.
FIG. 9 shows the vehicular child safety seat 1 in use. The vehicular child safety seat 1 is placed on a car seat 2 for supporting a juvenile 3 from below with the seat surface 11. A waist belt 5 partially forming a seat belt provided on the car is extended over the vehicular child safety seat 1. The waist belt 5 is introduced into a notch of one of the side walls 12 through slits 15 and engaged with the waist belt engaging portion 13. A tongue plate 6 provided on the forward end of the waist belt 5 is connected with a buckle 7 for completely fastening the seat belt and simultaneously fixing the vehicular child safety seat 1 and the juvenile 3 to the car seat 2.
The shoulder belt 4 extending over the juvenile 3 obliquely from above is passed through one of the slits 15 and engaged with the shoulder belt engaging portion 14 provided on the side wall 12. The seat surface 11 of the vehicular child safety seat 1 is positioned higher than the seat surface of the car seat 2, and hence the shoulder belt 4 can be correctly extended over the shoulders of the juvenile 3 without hanging on the face of the juvenile 3 having a short trunk.
The size of the body of the juvenile 3 using the vehicular child safety seat 1 depends on the individual variation or the age of the juvenile 3. In the conventional vehicular child safety seat 1, however, the vertical position for extending the waist belt 5 is set constant in response to that of the waist belt engaging portion 13. The vertical position of the waist belt engaging portion 13 partially forming the fixed side wall 12 cannot be changed. When the juvenile 3 is of large build, therefore, the waist belt 5 may disadvantageously press the abdominal region.